| Message ID | 152902119090.4144.9561910674530214291.stgit@pluto.themaw.net (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Fri, 2018-06-15 at 08:06 +0800, Ian Kent wrote: Opps, missing Signed-off-by, please add it! > Depending on how it is configured the autofs user space daemon can > leave in use mounts mounted at exit and re-connect to them at start > up. But for this to work best the state of the autofs file system > needs to be left intact over the restart. > > Also, at system shutdown, mounts in an autofs file system might be > umounted exposing a mount point trigger for which subsequent access > can lead to a hang. So recent versions of automount(8) now does its > best to set autofs file system mounts catatonic at shutdown. > > When autofs file system mounts are catatonic it's currently possible > to create and remove directories and symlinks which can be a problem > at restart, as described above. > > So return EACCES in the directory, symlink and unlink methods if the > autofs file system is catatonic. Signed-off-by: Ian Kent <raven@themaw.net> > --- > fs/autofs/root.c | 33 ++++++++++++++++++++++++++++++--- > 1 file changed, 30 insertions(+), 3 deletions(-) > > diff --git a/fs/autofs/root.c b/fs/autofs/root.c > index a3d414150578..782e57b911ab 100644 > --- a/fs/autofs/root.c > +++ b/fs/autofs/root.c > @@ -559,6 +559,13 @@ static int autofs_dir_symlink(struct inode *dir, > if (!autofs_oz_mode(sbi)) > return -EACCES; > > + /* autofs_oz_mode() needs to allow path walks when the > + * autofs mount is catatonic but the state of an autofs > + * file system needs to be preserved over restarts. > + */ > + if (sbi->catatonic) > + return -EACCES; > + > BUG_ON(!ino); > > autofs_clean_ino(ino); > @@ -612,9 +619,15 @@ static int autofs_dir_unlink(struct inode *dir, struct > dentry *dentry) > struct autofs_info *ino = autofs_dentry_ino(dentry); > struct autofs_info *p_ino; > > - /* This allows root to remove symlinks */ > - if (!autofs_oz_mode(sbi) && !capable(CAP_SYS_ADMIN)) > - return -EPERM; > + if (!autofs_oz_mode(sbi)) > + return -EACCES; > + > + /* autofs_oz_mode() needs to allow path walks when the > + * autofs mount is catatonic but the state of an autofs > + * file system needs to be preserved over restarts. > + */ > + if (sbi->catatonic) > + return -EACCES; > > if (atomic_dec_and_test(&ino->count)) { > p_ino = autofs_dentry_ino(dentry->d_parent); > @@ -697,6 +710,13 @@ static int autofs_dir_rmdir(struct inode *dir, struct > dentry *dentry) > if (!autofs_oz_mode(sbi)) > return -EACCES; > > + /* autofs_oz_mode() needs to allow path walks when the > + * autofs mount is catatonic but the state of an autofs > + * file system needs to be preserved over restarts. > + */ > + if (sbi->catatonic) > + return -EACCES; > + > spin_lock(&sbi->lookup_lock); > if (!simple_empty(dentry)) { > spin_unlock(&sbi->lookup_lock); > @@ -735,6 +755,13 @@ static int autofs_dir_mkdir(struct inode *dir, > if (!autofs_oz_mode(sbi)) > return -EACCES; > > + /* autofs_oz_mode() needs to allow path walks when the > + * autofs mount is catatonic but the state of an autofs > + * file system needs to be preserved over restarts. > + */ > + if (sbi->catatonic) > + return -EACCES; > + > pr_debug("dentry %p, creating %pd\n", dentry, dentry); > > BUG_ON(!ino); > > -- > To unsubscribe from this list: send the line "unsubscribe autofs" in
diff --git a/fs/autofs/root.c b/fs/autofs/root.c index a3d414150578..782e57b911ab 100644 --- a/fs/autofs/root.c +++ b/fs/autofs/root.c @@ -559,6 +559,13 @@ static int autofs_dir_symlink(struct inode *dir, if (!autofs_oz_mode(sbi)) return -EACCES; + /* autofs_oz_mode() needs to allow path walks when the + * autofs mount is catatonic but the state of an autofs + * file system needs to be preserved over restarts. + */ + if (sbi->catatonic) + return -EACCES; + BUG_ON(!ino); autofs_clean_ino(ino); @@ -612,9 +619,15 @@ static int autofs_dir_unlink(struct inode *dir, struct dentry *dentry) struct autofs_info *ino = autofs_dentry_ino(dentry); struct autofs_info *p_ino; - /* This allows root to remove symlinks */ - if (!autofs_oz_mode(sbi) && !capable(CAP_SYS_ADMIN)) - return -EPERM; + if (!autofs_oz_mode(sbi)) + return -EACCES; + + /* autofs_oz_mode() needs to allow path walks when the + * autofs mount is catatonic but the state of an autofs + * file system needs to be preserved over restarts. + */ + if (sbi->catatonic) + return -EACCES; if (atomic_dec_and_test(&ino->count)) { p_ino = autofs_dentry_ino(dentry->d_parent); @@ -697,6 +710,13 @@ static int autofs_dir_rmdir(struct inode *dir, struct dentry *dentry) if (!autofs_oz_mode(sbi)) return -EACCES; + /* autofs_oz_mode() needs to allow path walks when the + * autofs mount is catatonic but the state of an autofs + * file system needs to be preserved over restarts. + */ + if (sbi->catatonic) + return -EACCES; + spin_lock(&sbi->lookup_lock); if (!simple_empty(dentry)) { spin_unlock(&sbi->lookup_lock); @@ -735,6 +755,13 @@ static int autofs_dir_mkdir(struct inode *dir, if (!autofs_oz_mode(sbi)) return -EACCES; + /* autofs_oz_mode() needs to allow path walks when the + * autofs mount is catatonic but the state of an autofs + * file system needs to be preserved over restarts. + */ + if (sbi->catatonic) + return -EACCES; + pr_debug("dentry %p, creating %pd\n", dentry, dentry); BUG_ON(!ino);